I've been pretty happy using 7.3+CR/7.4 as PVHVM for the last week or two now, no complaints other than the sudden problem with PV taking me by surprise. Has anyone tried with 7.4 as the dom0 yet? I saw the point in the 7.4 release notes about enough rebasing taking place that I probably shouldn't update my xen hypervisor machines yet...but wondering what the status is on that. Thanks, -Dave > On Sep 14, 2017, at 4:00 AM, Adi Pircalabu <adi at ddns.com.au> wrote: > > On 14-09-2017 20:57, Adi Pircalabu wrote: >> On 08-09-2017 6:17, Kevin Stange wrote: >>> On 09/06/2017 05:21 PM, Kevin Stange wrote: >>>> On 09/06/2017 08:40 AM, Johnny Hughes wrote: >>>>> On 09/05/2017 02:26 PM, Kevin Stange wrote: >>>>>> On 09/04/2017 05:27 PM, Johnny Hughes wrote: >>>>>>> On 09/04/2017 03:59 PM, Kevin Stange wrote: >>>>>>>> On 09/02/2017 08:11 AM, Johnny Hughes wrote: >>>>>>>>> On 09/01/2017 02:41 PM, Kevin Stange wrote: >>>>>>>>>> On 08/31/2017 07:50 AM, PJ Welsh wrote: >>>>>>>>>>> A recently created and fully functional CentOS 7.3 VM fails to boot >>>>>>>>>>> after applying CR updates: >>>>>>>>>> <snip> >>>>>>>>>>> Server OS is CentOS 7.3 using Xen (no CR updates): >>>>>>>>>>> rpm -qa xen\* >>>>>>>>>>> xen-hypervisor-4.6.3-15.el7.x86_64 >>>>>>>>>>> xen-4.6.3-15.el7.x86_64 >>>>>>>>>>> xen-licenses-4.6.3-15.el7.x86_64 >>>>>>>>>>> xen-libs-4.6.3-15.el7.x86_64 >>>>>>>>>>> xen-runtime-4.6.3-15.el7.x86_64 >>>>>>>>>>> uname -a >>>>>>>>>>> Linux tsxen2.xx.com <https://urldefense.proofpoint.com/v2/url?u=http-3A__tsxen2.xx.com&d=DwICAg&c=C3yme8gMkxg_ihJNXS06ZyWk4EJm8LdrrvxQb-Je7sw&r=YXRZwMwEbTMJ1t85qnlbGKfbihJPB3W_h8JMF05uQhA&m=nL_mZmY1UFFXIyjRjNDnOYF72oaFqTb61_8qV-7trBA&s=9Xwh4UrRbSxWCPu--RHK9tBDn_So4wqFK0VOVLiP15s&e= > 4.9.39-29.el7.x86_64 #1 SMP >>>>>>>>>>> Fri Jul 21 15:09:00 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux >>>>>>>>>>> Sadly, the other issue is that the grub menu will not display for me to >>>>>>>>>>> select another kernel to see if it is just a kernel issue. >>>>>>>>>>> The dracut prompt does not show any /dev/disk folder either. >>>>>>>>>> I'm seeing this as well. My host is 4.9.44-29 and Xen 4.4.4-26 from >>>>>>>>>> testing repo, my guest is 3.10.0-693.1.1. Guest boots fine with >>>>>>>>>> 514.26.2. The kernel messages that appear to kick off the failure for >>>>>>>>>> me start with a page allocation failure. It eventually reaches dracut >>>>>>>>>> failures due to systemd/udev not setting up properly, but I think the >>>>>>>>>> root is this: >>>> <snip> >>>>>>>>> Do any of you guys have access to RHEL to try the RHEL 7.4 Kernel? >>>>>>>> I think I may. I haven't tried yet, but I'll see if I can get my hands >>>>>>>> on one and test it tomorrow when I'm back at the office tomorrow. >>>>>>>> RH closed my bug as "WONTFIX" so far, saying Red Hat Quality Engineering >>>>>>>> Management declined the request. I started to look at the Red Hat >>>>>>>> source browser to see the list of patches from 693 to 514, but getting >>>>>>>> the full list seems impossible because the change log only goes back to >>>>>>>> 644 and there doesn't seem to be a way to obtain full builds of >>>>>>>> unreleased kernels. Unless I'm mistaken. >>>>>>>> I will also do some digging via RH support if I can. >>>>>>> I would think that RH would want AWS support for RHEL 7.4 and I thought >>>>>>> AWS was run on Xen // Note: I could be wrong about that. >>>>>>> In any event, at the very least, we can make a kernel that boots PV for >>>>>>> 7.4 at some point. >>>>>> AWS does run on Xen, but the modifications they make to Xen are not >>>>>> known to me nor which version of Xen they use. They may also run the >>>>>> domains as HVM, which seems to mitigate the issue here. >>>>>> I just verified this kernel issue exists on a RHEL 7.3 system image >>>>>> under the same conditions, when it's updated to RHEL 7.4 and kernel >>>>>> 3.10.0-693.2.1.el7.x86_64. >>>>> One other option is to run the DomU's as PVHVM: >>>>> https://urldefense.proofpoint.com/v2/url?u=https-3A__wiki.xen.org_wiki_Xen-5FLinux-5FPV-5Fon-5FHVM-5Fdrivers&d=DwICAg&c=C3yme8gMkxg_ihJNXS06ZyWk4EJm8LdrrvxQb-Je7sw&r=YXRZwMwEbTMJ1t85qnlbGKfbihJPB3W_h8JMF05uQhA&m=nL_mZmY1UFFXIyjRjNDnOYF72oaFqTb61_8qV-7trBA&s=O2qKd2kfvOIH5E9Ndt3WhhHlOdvQQseXJtTNtriIftg&e= That should be much better performance than HVM and may be a workable >>>>> solution for people who don't want to modify their VM kernel. >>>>> Here is more info on PVHVM: >>>>> https://urldefense.proofpoint.com/v2/url?u=https-3A__wiki.xen.org_wiki_PV-5Fon-5FHVM&d=DwICAg&c=C3yme8gMkxg_ihJNXS06ZyWk4EJm8LdrrvxQb-Je7sw&r=YXRZwMwEbTMJ1t85qnlbGKfbihJPB3W_h8JMF05uQhA&m=nL_mZmY1UFFXIyjRjNDnOYF72oaFqTb61_8qV-7trBA&s=KEvkgBy5Xk4kxaQvwzaOy78t7rk2YrRT0Amziht84lc&e= ================ >>>>> Also heard from someone to try this Config file change to the base >>>>> kernel and rebuild: >>>>> CONFIG_RANDOMIZE_BASE=n >>>> This suggestion was mirrored in the RH bugzilla as well, it worked, but >>>> the same issue does not exist in newer kernels which have the option on. >>>> I've posted updated findings in the CentOS bug, which includes a patch >>>> that I found which seems to fix the issue: >>>> https://urldefense.proofpoint.com/v2/url?u=https-3A__bugs.centos.org_view.php-3Fid-3D13763-23c30014&d=DwICAg&c=C3yme8gMkxg_ihJNXS06ZyWk4EJm8LdrrvxQb-Je7sw&r=YXRZwMwEbTMJ1t85qnlbGKfbihJPB3W_h8JMF05uQhA&m=nL_mZmY1UFFXIyjRjNDnOYF72oaFqTb61_8qV-7trBA&s=sCwMApzGOUMUvb6ZockhNOmVfISaRBhCxoyLa8UeB84&e= >>> With many thanks to hughesjr and toracat, I was able to find a patch >>> that seems to resolve this issue and get it into CentOS Plus >>> 3.10.0-693.2.1. I've asked Red Hat to apply it to some future kernel >>> update, but that is only a dream for now. >>> In the meantime, if anyone who has been experiencing the issue with PV >>> domains can try out the CentOS Plus kernel here and provide feedback, >>> I'd appreciate it! >>> https://urldefense.proofpoint.com/v2/url?u=https-3A__buildlogs.centos.org_c7-2Dplus_kernel-2Dplus_20170907163005_3.10.0-2D693.2.1.el7.centos.plus.x86-5F64_&d=DwICAg&c=C3yme8gMkxg_ihJNXS06ZyWk4EJm8LdrrvxQb-Je7sw&r=YXRZwMwEbTMJ1t85qnlbGKfbihJPB3W_h8JMF05uQhA&m=nL_mZmY1UFFXIyjRjNDnOYF72oaFqTb61_8qV-7trBA&s=EZkVPbptzzbEVFWx9JUHAWKy61l6LsCLVSEp14VI-HA&e= >> Loaded 3.10.0-693.2.2.el7.centos.plus.x86_64 successfully on two >> CentOS 7.4 PV domUs which failed previously on >> kernel-3.10.0-693.2.2.el7.x86_64, the 2 hypervisors tested are: >> 1. CentOS 6.9, kernel 4.9.13-22.el6.x86_64, Xen 4.6.3-8.el6 >> 2. CentOS 7.3, kernel 4.9.31-27.el7.x86_64, Xen 4.9.31-27.el7.x86_64 > > Should read: > 1. CentOS 6.9, kernel 4.9.13-22.el6.x86_64, Xen 4.6.3-8.el6 > 2. CentOS 7.3, kernel 4.9.31-27.el7.x86_64, Xen 4.6.3-15.el7 > > --- > Adi Pircalabu, System Administrator > _______________________________________________ > CentOS-virt mailing list > CentOS-virt at centos.org > https://urldefense.proofpoint.com/v2/url?u=https-3A__lists.centos.org_mailman_listinfo_centos-2Dvirt&d=DwICAg&c=C3yme8gMkxg_ihJNXS06ZyWk4EJm8LdrrvxQb-Je7sw&r=YXRZwMwEbTMJ1t85qnlbGKfbihJPB3W_h8JMF05uQhA&m=nL_mZmY1UFFXIyjRjNDnOYF72oaFqTb61_8qV-7trBA&s=gCcWg7R3JYkD_vQZomlBE7lhDcYMi8TvZEymITpYGbI&e=